AIM: To investigate the changes and related factors of choroidal thickness(CT)in acute primary angle-closure glaucoma(APACG), and chronic primary angle-closure glaucoma(CPACG).METHODS: It was a retrospective study. A total of 35 patients(43 eyes)with APACG, 26 patients(46 eyes)with CPACG and 46 patients(81 eyes)with normal eye condition and used as the control group in the study. EDI-OCT was used to measure and compare the foveal, nasal, temporal, superior and inferior CT of APACG, CPACG and normal control groups. The CT were labeled as subfoveal choroidal thickness(SFCT), nasal 2mm(N 2mm), temporal 2mm(T 2mm), superior 2mm(S 2mm), inferior 2mm(I 2mm).Linear regression analysis was used to explore the related factors of CT. Logistic regression analysis was used to evaluate the association between CT and presence of APACG and CPACG.RESULTS: There was no significant difference in CT of APACG, CPACG and normal control group(P>0.05). CT of all sites was negatively correlated with axial length(AL). N 2 mm and I 2 mm were also negatively correlated with age, anterior chamber depth(ACD), SFCT was negatively correlated with age and AL(P<0.05). Multivariate Logistic analysis showed that there was an association between S 2mm and APACG(P=0.029), the odds ratio(OR)and 95% confidence interval(CI)was 0.975(0.953, 0.997). There was no association between CPACG and CT at all locations(P>0.05).CONCLUSION: Age, AL and ACD are the factors that related to choroidal thickness. It is also confirm that there is an association between decreased S 2mm and APACG. However, there is no correlation between CPACG and CT at all locations.